In light of the adopted green policies and strategies, thermal plasmas are gaining interest as a potential solution to electrify the industry, particularly for endothermic processes, for their tunable enthalpy and the absence of direct CO₂ emissions. However, the majority of industrial applications of thermal plasma technologies are at atmospheric or lower pressure, whether for material processing, waste treatment, gasification, assisted combustion or in electric arc furnaces. Very little information exists on thermal plasmas at pressures above 1 bar, with the majority of academic publications using either analytical or numerical methodologies. The main experimental high-pressure plasma studies conducted date back to the 1960s, the 1970s and 1980s mainly in the US and the EU for aerospace applications, in addition to gas blast circuit breaker and underwater welding applications. However, these systems operate only for a few milliseconds to a few minutes at most. The interest in operating plasma systems at high-pressure is on one hand to reduce the volume of the facilities, and therefore, global costs, and on the other hand, is of practical necessity such as the case of underwater welding and in aerospace application where plasma technology plays a role in duplicating the conditions to which a vehicle is exposed to in atmospheric entry/reentry. This paper reports a thorough literature review on all high-pressure plasma arc studies available to date, including journal articles, books, and declassified reports. The findings of the studies are classified into four categories: DC and AC technologies, electrical characteristics, thermodynamics and heat transfer, and electrode erosion. The gaps and limitations are identified, and the main hypotheses are formulated, (re)opening the way for future high-pressure thermal plasma studies. Operating thermal plasma systems at high pressure could have considerable economic benefits, and thus, leading to competitive pricing for electrified high temperature processes, but faces many challenges.

鉴于所采用的绿色政策和战略，热等离子体作为行业电气化的潜在解决方案越来越受到人们的关注，特别是对于吸热过程，因为其可调节的焓和不存在直接CO ₂排放。然而，热等离子体技术的大多数工业应用都是在大气压或较低压力下进行，无论是用于材料加工、废物处理、气化、辅助燃烧还是电弧炉。关于压力高于 1 bar 的热等离子体的信息非常少，大多数学术出版物都使用分析或数值方法。主要的高压等离子体实验研究可以追溯到 20 世纪 60 年代、1970 年代和 1980 年代，主要在美国和欧盟进行航空航天应用，此外还有气体爆炸断路器和水下焊接应用。然而，这些系统最多只能运行几毫秒到几分钟。在高压下操作等离子系统的目的一方面是为了减少设施的体积，从而降低全球成本，另一方面，也是实际需要的，例如水下焊接和航空航天应用，其中等离子体技术在复制飞行器进入/再进入大气层时所面临的条件方面发挥着重要作用。本文对迄今为止所有高压等离子弧研究进行了全面的文献综述，包括期刊文章、书籍和解密报告。研究结果分为四类：直流和交流技术、电气特性、热力学和传热以及电极腐蚀。确定了差距和局限性，并制定了主要假设，（重新）为未来的高压热等离子体研究开辟了道路。在高压下运行热等离子体系统可以带来可观的经济效益，从而为电气化高温工艺带来有竞争力的价格，但也面临许多挑战。