China’s largest private chemical EPC (engineering, procurement, construction) contractor, Wison Engineering Ltd. (Wison; Shanghai; www.wison.com [http://www.wison.com]) has recently introduced details about its proprietary butadiene technology, which is set for commercialization. The process aims to meet the anticipated growth in annual butadiene consumption, which will “far exceed” global expansion in capacity, says Wison’s technical director and chief technologist, Yansheng Li. China, in particular, is seeing butadiene demand rising significantly due to the increasing number of synthetic rubber projects, he says.
In Wison’s butane process (flowsheet), butanes and lighter components are first separated in the C4 pre-separation unit. Butenes are then mixed with air and steam and dehydrogenated in the oxidative dehydrogenation (ODH) reactor. After recovering the heat, the reaction gas is further cooled and scrubbed to remove acids and other impurities, then compressed. Crude 1,3-butadiene (13BD) is recovered by an absorber/deabsorber unit, and then purified in a 13BD-extraction unit.
The ODH reaction features a new, patent-pending catalyst developed by Wison, which is based on the traditional B-02 (iron-based) catalyst technology. Compared to the traditional catalyst, the new catalyst achieves: a 3–4% increase in the conversion of butane to butene, to reach a conversion of 77–79% in a single-pass; and a 2–3% increase in the selectivity for 13BD, to reach a final selectivity of 92–94%, says Li. He also adds that the improved heat integration leads to a 15% reduction in utility consumption compared to existing technology.
The company has finished preliminary work for several projects in China, and is now in the final stages of completing a process-design package for a 75,000-ton/yr butadiene plant, says Li.
Media Source: Chemical Engineering
Writer: Gerald Ondrey
Issue: June 2013
Link: http://www.che.com/chementator/A-new-butadiene-process-is-set-for-commercialization_10566.html