Energy Efficiency Potential in Industry Sector
The bulk of energy-intensive industries include the iron, steel, metals, minerals and petrochemical industries. Together, they account for 50% of the total energy consumed by industry. Figure 5.2 below shows the variation of energy consumption between 2012 and 2035 (© OECD/IEA, Statistics 2015; © OECD/IEA, WEO 2012).
Reducing energy consumption in the industry sector can obviously be achieved by increasing the efficiency of all industries. There, the basic application of the most efficient technologies would lead to massive savings. The challenge of energy efficiency in the sector mainly depends on existing solutions. It can also be achieved by limiting (and then reducing) the energy consumption in energy-intensive industries, in particular, petrochemical industries.
Experts agree that up to 30% of the energy consumed could be saved in the petrochemical industry by using high-performing technologies (© OECD/IEA, Technology Industry 2009). These savings can be grouped into three main technology domains. First, optimizing the heat produced through process integration could lead to savings of around 5-10%. Then, using Combined Heating and Power plants (CHP) to supply petrochemical plants would save up to 20% on existing sites and between 5 and 10% on new sites. Combined Heating and Power directly reuses the heat generated by the production of electricity; in conventional supply systems, electricity is partially used to produce heat. Finally, recycling waste plastics (which are based on oil) could lead to 3% resource savings.
The deployment of these technologies however faces the reality of existing investments and the lifetime of existing sites, which obviously limit immediate
Fig. 5.2 Evolution of energy consumption in industry (© OECD/IEA, Statistics 2015; © OECD/ IEA, WEO 2012) savings. Most of the existing sites in OECD countries will not start revamping before 2040. However, the majority of industrial growth will be realized in new economies and by way of new plants being built, which therefore can be designed to incorporate new technologies right from the start. The production capacity in non-OECD countries shall be multiplied by four by 2050 (© OECD/IEA, OECD 2012; © OECD/IEA, Non-OECD 2012).
Important R&D has been devoted to rethink as well petrochemical processes with a view to optimizing them or to substitute oil. New production technologies using gas (less polluting than oil) and biomass could substitute classical naphtha steam cracking. Catalytic processing has already achieved yields of around 65% and engineers are working towards raising these to 80%. New separation methods, notably through the use of special membranes, could also lead to savings in the range of 5%, as the separation process accounts for around 45% of total energy consumption. Beyond these improvements, process intensification could lead to savings of up to 5% in the next decade, and probably up to 20% in the next 40 years. This intensification can be realized using different methods, including process miniaturization and thermodynamic improvement. Finally, better management of flows and return flows through improved time management can also lead to better efficiency of the overall process.
Other initiatives include replacing all plastics by new materials not based on primary fossil resources. Bioplastics could replace 80% of the world’s plastics, according to experts (© OECD/IEA, Technology Industry 2009). Furthermore, better waste treatment and the use of new materials offer considerable potential savings.
Finally, petrochemical plants generate a significant amount of greenhouse gas emissions. CO2 capture systems could be implemented to reduce the ecological impact of these plants.