Goal 9 of the United Nations’ Sustainable Development Goal (UN SDG) is to “build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation”.
One important target in Goal 9 is:
Target 9.4 - by 2030 upgrade infrastructure and retrofit industries to make them sustainable, with increased resource use efficiency and greater adoption of clean and environmentally sound technologies and industrial processes, all countries taking action in accordance with their respective capabilities.
CO2 emissions account for around 80% of all GHG emissions from man-made sources. Hence it is important to reduce CO2 emissions from these anthropogenic sources, especially manufacturing processes. Some of the major emitters include iron and steel industry and the chemical and petrochemical industry. Some of the following measures may be taken to improve energy efficiency of the plant, which will then lead to reduction of CO2 emissions:
- Insulation – better insulation means reduced losses and improved energy/utility usage. This is arguably the most practical and cost effective way for an energyefficient facility. For plants in temperate countries, good insulation keeps plants warmer in winter and cooler in the summer. Better insulation means reduced heat loss in the winter, and reduced cooling load during the summer.
- Lighting – In households, switching off lights when they are not in use is a practical way to save energy. This can be practised in the plants/factories too. Automated lighting systems may be installed for long term power savings too.
- Air conditioning – Power consumption of air conditioning units is estimated around 20 – 40 % of a typical building. Setting suitable temperature of air conditioning makes a better working environment and leads to reduced power consumption. It is also worth to replace old heating and cooling systems (older than 10 years) as the new units are far more efficient than old ones.
- Heat recovery – Many processes have excess of waste heat. These waste heat can be better utilised in most cases. One may recover the waste heat through waste heat boiler or heat exchanger.
- Greener fuel – Whenever possible, companies should explore the use of renewable energy, e.g. solar power, biomass for energy generation, combine heat and power scheme. The switch to lowcarbon energy can also be done at the country level, where policy measures can initiate the shift to a low-carbon regime. This is evident in the recent declaration of many major economies (e.g., UK, China, and Japan) to achieve net zero GHG emissions by about the middle of the century.
Apart from energy resource, one should also maximise the efficiency of material resources; the latter include water, utility gases, solvent and solid wastes. Some of the established techniques include:
- Reuse – Waste generated from one process may be utilised in another process as feed material.
- Recycle – Waste is channelled back to the process from which it originates.
- Regeneration – Waste material is partially purified for better reuse/recycle opportunity.
- Ecoindustrial park – Waste generated by a company is sent to another plant as feedstock.
These measures provide opportunities to operationalize the Circular Economy framework, which is supported by comprehensive policies in major economies such as the EU and China. Engineering models can facilitate implementation of Circular Economy initiatives at the level of individual companies or groups of cooperating firms.
Prof Dr Ir Dominic Foo is the Professor of Process Design and Integration at the University of Nottingham Malaysia Campus, and is the Founding Director for the Centre of Excellence for Green Technologies. Professor Raymond R. Tan is a full professor of chemical engineering, University Fellow and current Vice-Chancellor for Research and Innovation at De La Salle University, Manila, Philippines. Santanu Bandyopadhyay is currently Institute Chair Professor, Department of Energy Science and Engineering, at the Indian Institute of Technology Bombay (IIT Bombay). They are co-Editors in Chief, Process Integration and Optimization for Sustainability