Waste management is one of the greatest environmental challenges faced by the world at present. The continuous increase in waste generation is aggravating this problem. Managing this waste is an enormous challenge for communities around the globe. It is not just a matter of keeping streets clean, but also of finding ways to reduce landfill space and, perhaps most importantly, turn waste into useful resources.  An innovative approach to dealing with this problem is thermochemical processing, a technology that can convert waste and biomass into valuable resources. In addition to waste reduction, reusing, and recycling, the thermochemical processing of waste and biomass could be a potential solution to this environmental crisis. This process refers to converting waste into energy through chemical reactions at high temperatures, resulting in clean and renewable energy. The blog focuses on the numerous advantages and disadvantages of thermochemical processing of waste and biomass.

In addition to this, the shrinking supply of natural resources, increasing greenhouse emissions, and realization of the necessity for sustainable development in terms of safely reusing biomass, and the conversion of waste and biomass into valuable materials and energy appears to be a strong trend. The use of liquid fossil fuels and petroleum was 85.7 million barrels/day in 2008 and is expected to increase to 112.2 million barrels/day worldwide in 2035.

What is Thermochemical Processing?

Thermochemical processing is a term used for variety of processes wherein heat is used to break down waste into its component parts, which can then be used to create several products, including biofuels, chemicals, and electricity. This innovative technology is the best possible solution for managing waste as it reduces the amount of waste sent to landfills, generates valuable resources, and can help to reduce greenhouse gas emissions. Thermochemical conversion of biomass includes processes, for instance pyrolysis, through incineration, gasification, torrefaction, hydrothermal liquefaction, and carbonization. The end products from various technologies include electric power, heat, fuels, and chemicals.

Thermochemical processing Techniques:

            ·         Pyrolysis

There are various techniques that fall under Thermochemical processing. One such technique is pyrolysis. This involves heating waste in the absence of oxygen to break it down into its component parts. Through the use of pyrolysis, biomass can be converted into liquid fuels, namely, bio-oil, biodiesel and bioethanol.  Under this technology, waste materials are degraded thermally under limited supply of air or oxygen at 300–600 °C to produce energy in the form of fuel, biochar, syngas and biofuel precursors. The process is irreversible process and the materials which undergo the process are continuously subjected to changes in physical and chemical composition. The process is mainly used in chemical industries and useful in production of biochar, methanol and activated charcoal. The biochar obtained from the process is useful in heavy metal remediation, carbon sequestration, and as a soil conditioner. The char is equivalent for 6% of overall carbon content of the biomass.  After the treatment of gas, 52% of carbon content can be stored in carbon dioxide, while the remaining 42% are converted through Fischer- Tropsch (FT- synthesis).

            ·         Gasification

The other thermochemical process applied in waste management is gasification. This involves heating waste in the presence of a limited amount of oxygen. Gasification process produces a gas that can be used to generate electricity or heat, or it can be used as a fuel for vehicles. The producer gas can used as a direct fuel or can be converted into profitable products like H2, synthetic natural gas (methanation) and diesel, jet fuel, gasoline (Fischer–Tropsch diesel process), methanol, ethanol and dimethyl ether. The process is further categorized into steam gasification, supercritical water gasification and catalytic gasification. The further classification depends on the gasifying agent.

Gasification process is apt for converting biomass into useful chemicals and non-toxic fuels and while using existing infrastructure. For the process to be used on the industrial scale, further research on advancement is required to improve gas cleaning and lower the costs of highly effective processes. Hybrid renewable energy systems focused on thermochemical conversion are useful for tackling climate change and simultaneously overcoming energy challenges in certain regions. However, more work is required to be done on the ways to maximize renewable sources fraction while minimizing the costs, real life testing, etc. Moreover, carbon storage and capture technology in combination with sustainable biofuels production could help in achieving carbon negativity. International organizations such as International Energy Agency (IEA) and United Nations Industrial Development Organization (UNIDO) have underlined the significance of scaling up such technologies in the near future and the need for more research to be conducted in this direction so that Net Zero goals can be achieved.

Despite that many advantages offered by the gasification process, there are disadvantages associated with the process, such as high concentration of impurities such as tar, particulates, alkali chloride and sulfur species when syngas is sued for downstream application.

            ·         Hydrothermal & Solvent Liquefaction

Another widely used thermochemical process is hydrothermal liquefaction, which involves heating waste in water at high temperature and pressure. This technique produces a bio-oil, similar to pyrolysis, that can be used as a feedstock for the production of biofuels and chemicals. Like pyrolysis, solvent liquefaction can produce sugars from carbohydrate and phenolic compounds from lignin.

Solvent Liquefaction in water called hydrothermal processing is mainly attractive for wet feedstock, that can be managed as slurries with solid loadings. Moreover, hydrothermal processing can be used to hydrolyze the cellulose to glucose.

According to the TechSci Research report, " Biorefinery Market – Global Industry Size, Share, Trends, Competition, Opportunity and Forecast, 2018-2028F, Segmented By Product (Energy, Chemical and Material), By Production Facility Size (Small and medium-sized production facility, and large production facility), By Feedstock, (Primary Biomass and Secondary Biomass), By Process (Thermochemical, Biochemical, Chemical, and Mechanical & Thermomechanical), By Region, By Competition ", the global biorefinery market is anticipated to grow at a rapid rate in the forecast period, 2024-2028. The growth of the market is driven by various factors like growing interest in environmental sustainability, technological advancements and increasing investment in biorefinery market and innovations and development of biorefineries. Moreover, the demand for bioenergy and depletion of fossil fuels are also contributing to the market growth. Biorefinery has an advantage of producing multiple products and thereby maximizing the value derived from the feedstock.

The increase in GHG emissions has resulted in climate changes like uneven rainfall distribution, elevating sea levels, floods, draughts, extreme weather conditions. The use of biorefinery for production of biofuels is useful in this regard as biofuels are replacements for fossil fuels and can help mitigate greenhouse gas emissions and generate economic opportunities for consumers and businesses.

Impact of Russia-Ukraine War and Stringent Regulatory Environment

• The Russia-Ukraine war has had an immense effect on the energy systems due to the significant role of Russia in supplying natural gas and fertilizers globally and the extensive contribution of both Russia and Ukraine in exporting oilseeds to the international markets. However, a warning has been issued by the International Energy Agency regarding lowering of biofuel mandates, which could result in increasing petroleum demand and supply concerns. A systemic approach is required to analyze the war implications for the market.

Advantages and Disadvantages of Thermochemical Processing

Thermochemical processing of waste and biomass has numerous benefits, making it suitable technology for sustainable waste management. Firstly, the technology reduces the amount of waste that is sent to landfills, which can help to reduce the environmental impact of waste management. Additionally, thermochemical processes generate valuable resources like biofuels and chemicals, which can be used to replace traditional fossil fuels and reduce greenhouse gas emissions. This technology also helps to create a circular economy in which waste is turned into a resource, thereby reducing the amount of virgin materials needed.

The several benefits of thermochemical processing reach far beyond waste management and into the broader arena of sustainable energy production. By converting waste and biomass into biofuels and other resources, thermochemical processing helps to reduce reliance on fossil fuels and promote the use of renewable energy. Furthermore, the gas produced by gasification can be used to generate electricity, which can help to reduce dependence on traditional power sources.

Although the technology has many benefits, it is not without its challenges. One of the primary challenges is the need for a reliable source of waste and biomass feedstock. This can be especially difficult in urban areas, where waste is often mixed and difficult to separate. Another challenge is the high energy input required to operate thermochemical processing facilities, which can be a significant barrier to widespread adoption. Lastly, the process of thermal conversion requires high temperatures, which makes it unsuitable for some types of waste materials like mixed waste and hazardous waste.

Environmental Considerations

The biofuels obtained from biomass have several advantages in comparison to gasoline and diesel derived from petroleum. One of the major benefits is the net reductions in greenhouse gases (GHG) emissions. Biofuels have a larger variation in GHG emissions when comparison to conventional fuels. This can be attributed to the fact that these technologies have different maturity levels. The application of fossil fuels for the biomass production and processing of biomass leads to net GHG emissions associated with the use of biofuels.

Economic Considerations

There are several factors that affect the economic benefits of supercritical water gasification process, including operation condition, yield and system capacity. The increase in system capacity, and feedstock concentration, along with reaction temperature can help in reducing hydrogen production cost.

Sensitivity analysis showed that sewage sludge treatment had a great economic impact than bio-heavy oil price.

The commercialization of second-generation biofuels is limited to their high product cost, which is greater than fossil fuels.

Future of Thermochemical Processing

Thermochemical processing is still an emerging technology, and its future is promising. Advancements in technology and infrastructure development may improve the efficiency and cost-effectiveness of the process. Additionally, the benefits of this process are becoming increasingly apparent, and it could potentially replace fossil fuels in the future.

The agricultural biomass, energy grass, and woody biomass can be utilized for feedstocks for the application of thermochemical conversion processes in biorefinery. There is development in the efforts to reduce the biomass feed cost. These include reducing shipping costs, optimizing biomass collection systems, and developing collection systems. There are two general conceptual modes of bio-refinery operations, including centralized conversion and decentralized conversion.

According to TechSci Research report, “India Biomass Market By Type (Natural Biomass, Residual Biomass, and Biomass Produced By Energy Crops), By Technology (Thermochemical, Biochemical), By Products (Biopower, Transportation Fuels, Biogas, and Biomaterials), By End Use (Industrial, Transportation, Residential, Utility, and Commercial), By Region, Competition, Forecast and Opportunities, 2019-2029F”, the India biomass market is project robust growth during the forecast period because India is aiming to reduce its reliance on fossil fuels in its journey to reach net-zero emissions by 2070. The country has currently an installed capacity of 10.2 GW for biomass production. Moreover, investments and collaborations in biomass energy ecosystem is likely to present several opportunities for organizations to make climate-smart decisions and reach net-zero carbon emission goal.

Recent Developments in the Market

In March 2021, Valero Energy Corporation and BlackRock's Global Energy & Power Infrastructure Fund formed a partnership with Navigator Energy Services to develop an industrial scale carbon capture pipeline system (CCS). A CCS offers energy transition through innovation in renewables like biorefineries.

In April 2021, Honeywell and Brazil based ECB Group formed a collaboration for the use of UOP Ecofining process to enable conversion of vegetable oils and inedible animal fats into renewable jet and diesel fuel.

Researchers are focusing on finding the potential of combining fossil fuels with sustainably grown biomass in flexible conversion facilities to produce fuels and other products. Gasification-based conversion platforms provide a flexible method for fuel production from biomass, coal, and natural gas. The application of biomass in the industry in place of fossil fuels has a plethora of potential use in small and medium-scale heat and power, fuel substitution in cement kilns, and injection in blast furnace steel and iron-making.

Conclusion:

Thermochemical processing of waste and biomass is an innovative and sustainable technology that holds enormous promise for managing waste and creating valuable resources. By turning waste into biofuels, chemicals, and other valuable resources, this approach can help to reduce reliance on fossil fuels, reduce greenhouse gas emissions, and promote a circular economy. While there are challenges to the widespread adoption of this technology, it offers significant promise for sustainable waste management and energy systems worldwide. As we continue to seek out innovative solutions for the challenges of the 21st century, thermochemical processing is a technology that deserves our careful consideration and support.

In conclusion, the problem of waste management requires a concerted effort to mitigate, and thermochemical processing of waste offers a potential solution to this problem. While the process has its disadvantages like atmospheric pollution, the advantages outweigh the disadvantages. The process reduces waste volume, produces clean and renewable energy, and creates job opportunities. Thermochemical processing has many applications and could potentially replace fossil fuels in various industries and transportation. As technology advancements continue, the cost-effective nature of the process may also improve, making thermochemical processing of waste a promising solution to the waste management crisis.