Process Engineer Contract Jobs in London

As a contract Process Engineer, you are hired to design, optimise, and troubleshoot the industrial processes used in chemical, pharmaceutical, food and beverage, oil and gas, utilities, and manufacturing environments to convert raw materials into finished products. The work involves developing process flow diagrams and piping and instrumentation diagrams, conducting mass and energy balance calculations, specifying and sizing equipment including vessels, heat exchangers, pumps, and compressors, participating in HAZOP and safety reviews, supporting the commissioning and startup of new processes, and identifying and implementing efficiency improvements in existing operations. Process Engineer contractors are brought in on capital projects during the design and commissioning phases, for process optimisation studies, and to provide specialist expertise in specific process technologies.

The technical skills expected of Process Engineer contractors depend on the sector and the nature of the process being designed or optimised. Chemical and oil and gas Process Engineers need proficiency in process simulation software such as Aspen HYSYS or CHEMCAD for modelling steady-state and dynamic process behaviour. Pharmaceutical process engineers need familiarity with process validation methodology, GMP requirements for process design, and the documentation standards required for regulatory submission. Food and beverage Process Engineers need knowledge of food safety and hygiene requirements, thermal processing, and the specific equipment used in food production. Across all Process Engineer disciplines, experience participating in HAZOP studies, interpreting P&IDs, and working within a process safety management framework is a fundamental expectation for all but the most junior roles.

Process Engineer contracting is steadily active across the oil and gas, pharmaceutical, chemical, and food manufacturing sectors. The substantial investment in new pharmaceutical manufacturing capacity, particularly for biologic and advanced therapy products, has generated significant process engineering contract demand. The energy sector, including both conventional oil and gas processing and the growing hydrogen and low-carbon fuels market, continues to provide a steady pipeline of process engineering contract work. The food and beverage industry generates consistent demand for process contractors with knowledge of food-grade materials, hygiene design principles, and the regulatory requirements of food production. Day rates are shaped by the specialist technical knowledge and often safety-critical context of process engineering work.

London dominates the UK contractor market by volume, depth, and rate levels. The capital concentrates the headquarters and major offices of most FTSE 100 companies, the largest global banks, the Big Four professional services firms, and the central government departments that collectively generate the majority of UK contract demand. Every contracting discipline covered on this site has active demand in London, from niche specialisms like threat intelligence and LLM engineering through to high-volume disciplines like project management and business analysis. The sheer density of employers means contractors in London typically have more choice of engagement at any given time than anywhere else in the UK. Day rates carry a premium of 15 to 25 per cent over the national average across most disciplines, reflecting both the concentration of complex, high-value programmes and the cost of operating in the capital.

Contract rates for process engineer roles in London typically range from £385 to £715 per day, depending on the scope of the role, required expertise, and the delivery expectations of the engagement.

Over the past twelve months, we have tracked over 150 process engineer contract roles across the site, with London accounting for roughly one in three of those. Data reviewed up to March 2026.